cis-ubuntu2004-v300-3-2-1

name	cis-ubuntu2004-v300-3-2-1
description	Ensure dccp kernel module is not available
category	cis-networking
version	3.0.0
author	cyberstrike-official
tags	["cis","ubuntu","linux","ubuntu-20.04","kernel-module"]
cis_id	3.2.1
cis_benchmark	CIS Ubuntu Linux 20.04 LTS Benchmark v3.0.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

3.2.1 Ensure dccp kernel module is not available (Automated)

Profile

• Level 2 - Server
• Level 2 - Workstation

Description

The Datagram Congestion Control Protocol (DCCP) is a transport layer protocol that supports streaming media and telephony. DCCP provides a way to gain access to congestion control, without having to do it at the application layer, but does not provide in-sequence delivery.

Rationale

• IF - the protocol is not required, it is recommended that the drivers not be installed to reduce the potential attack surface.

Impact

None expected if the DCCP protocol is not in use.

Audit Procedure

Command Line

Verify the dccp kernel module is not available on the system or has been disabled. This can be verified by performing the following or by running the audit script included below.

Run the following script to determine if the dccp kernel module is available on the system:

#!/usr/bin/env bash

{
  l_mod_name="dccp" l_mod_type="net"
  while IFS= read -r l_mod_path; do
      if [ -d "$l_mod_path/${l_mod_name//\-/\/}" ] && [ -n "$(ls -A "$l_mod_path/${l_mod_name//\-/\/}")" ]; then
          printf '%s\n' "$l_mod_name exists in $l_mod_path"
      fi
  done < <(readlink -f /usr/lib/modules/**/kernel/$l_mod_type || readlink -f
/lib/modules/**/kernel/$l_mod_type)
}

If nothing is returned, the dccp kernel module is not available on the system and no further audit steps are required. Note: Some systems may include the dccp filesystem as part of the kernel opposed to being available as a kernel module. In this case, the above audit will not return anything. This is also considered a passing state.